1. Field of the Invention
The present invention relates generally to devices that assist in the play of golf, and more particularly, to a distance-indicating device for allowing golf players to make a quick estimate of the distance between their ball position on the fairway and the center of the green.
2. Brief Description of the Prior Art
For the purpose of making it easier to select the proper golf club and speeding up the play on a golf course, distance markers are placed on course fairways. Distance markers provide players a quick estimate of the distance between the ball's position on the fairway and the center of the green. It is common for these markers to be permanently fixed to the ground so that they can not be easily moved. Some golf courses use sprinkler heads as distance markers. This method of distance marking is useful since each fairway is equipped with numerous sprinkler heads and such heads remain at fixed positions.
A major problem that exists with such markers is that they rise above ground level and interfere with maintenance operations conducted on the fairways (e.g. grass cutting). These devices must either be removed prior to grass cutting or must be avoided by the mowers. In either case the maintenance operations are impeded. In the first instance, the mowing operation is slowed down by the constant removal and reinstallation of the markers. In the second instance, the grass cutting around the markers cannot be done by large-scale cutters without damaging the markers. Thus, alternative cutting mechanisms must be employed to cut the grass.
One prior art solution to this problem is to have markers that are level with respect to the surrounding ground so as not to impede these fairway maintenance operations. The teaching of Zausmer (U.S. Pat. No. 3,599,981) is an example of such a marker. In Zausmer, the marker is comprised of a base plate and a top plate. The base plate has a plurality of pins having cone-shaped barbs on the ends, and numerals raised upwards from the base. The barbs anchor the base plate permanently into the fairway turf. The raised numerals indicate the applicable fairway distance. The top plate is attached to the base plate, and features a cutout that frames the numerals rising up from the base plate. Markers of this type fail to provide easily visible information to golfers during the course of play. The numerals on such a marker are virtually invisible to a golfer standing any distance away from the marker. The numerals would only be visible if the golfer were standing overhead or virtually next to the marker. Thus, in many cases the golfer will not see the marker and therefore will not be assisted in calculating the distance from his ball to the green.
Another prior art solution provides markers with elastically deformable visible elements rising above the level of the surrounding fairway turf, which are not damaged even when run over by fairway maintenance equipment. The teaching of Carman (U.S. Pat. No. 4,489,669) is an example of such a marker. Carman's marker comprises an elastic dome connected to a base. The dome extends upward from the base, rises above ground level, and may be inscribed with numerals to indicate range distances along the fairway. Although a golfer does not have to stand over the element to read the distance, as in the Zausmer teaching, because of the curved surface the distance at which the inscribed numerals are visible is still quite limited.
A significant shortcoming of the Carman-type markers is that its visible element deforms rather than collapses out of the way of potentially damaging devices. When the element encounters a sufficient pressure only the localized area in contact with the force deforms: a simultaneous collapse of the entire element does not occur. Areas that are not exposed to such sufficient pressure remain elevated above the ground and may be damaged by the oncoming mower device.
Another signal or marker found in the prior art, although not specifically utilized on golf fairways as a yardage marker, is disclosed by Vogeler (U.S. Pat. No. 1,771,667). Vogeler's ancient marker device, installed in a roadway and used as a traffic signal, includes a casing, a resiliently biased post centrally disposed within the casing and mounted thereto to slide vertically, a plurality of segments with their upper ends hingedly supported at the upper end of the post and with the segment's lower end slidably mounted within the casing.
In operation, the marker is installed at traffic intersections, and its segments, elevated above the road surface, are inscribed with cautionary words (i.e. "STOP", "GO", etc). If a motor vehicle is driven over the marker, the vehicle weight will cause the several segments to move downwardly thereby imparting a downward motion, via the post, to all of the remaining segments. Once the vehicle weight is removed, the spring-biased post will restore the segments to their respective normal positions.
If the Vogeler marker was installed on a golf fairway it would be quickly rendered inoperable. More specifically, the Vogeler marker's segments are hinged at their upper ends and slidably mounted at their lower ends. Due to the slidably mounted support configuration, the marker has gaps or openings existing between adjacent segments at their lower ends. Since these gaps would be located close to the fairway surface, grass clippings and other fairway debris could easily invade the marker, through the gaps, such that over a period of several grass cutting sessions, the clippings and debris would accumulate and block the lower segment ends from freely sliding, thereby impeding both the collapsibility of the marker and its return to an upstanding position. It should be noted that, in contrast to the lower end of the segments, clippings and debris can not enter between the upper end, hinged joints and impede the collapsibility of the marker because, due to the hinged manner of support, there are no gaps between the adjacent segments at their upper ends.
Finally, the prior art discloses using a system of determining the distance from a point on the fairway to its associated green. KARSTEN PING discloses a system wherein a plurality of yardage markers are disposed at twenty-five yard intervals along the fairway. Each marker, set at ground level, displays the distance from its location on the fairway to various points on the green. Since the markers used in the KARSTEN PING system are set at ground level they have the same shortcomings as those identified with the Zausmer markers. That is, markers of this type can only be read by golfers standing overhead or virtually next to the marker. Golfers positioned any distance away from the marker cannot read the range information stamped on the marker and in many cases cannot even see the marker itself. Thus, a system utilizing such flat markers cannot assist the golfer in calculating the distance from his ball to the green.